Expansion joint



Patented Oct. 30, '1928.

UNITED STATES PFATENT OFFICE.

ammo. mscrma, or onroaco, rumors.

nxrnnsron JOINT.

No Drawing. Application filed my 3,1926. SerialNo. 106,561.

My invention relates in general to e'xpanerly. As another extreme the joint must also sion joints, and has particular reference to perform properly at higher temperatures, expansion joint materials for use in concrete ranging from 70 to 115 F. From the above or the like constructions, particularly con- 1t (Ill be e n h t the joint is called upon to t rogfd tru ti b id b k function properly at one extreme temperature Waters, and other like constructions in which as Well as another extreme. These severe expansion and contraction of the concrete is tests make it necessary to go to considerable to be provided for by expansion contraction xp i prov-iding a material which will joint material, arranged in the form of strips a ptable, and these requirements, as at spaced intervals in the concrete structure. above t a j ften dlfiicultto O G Ih These expansion contraction joints are Th primary ob ect of mylnvention is to usually .provided .in' ,either of two Ways. PIQV e 3 1 1} 1 nt met llal'whieh Will One way being to leave a space between sec-" lheet the requnements and properly functions of the concrete with the space fillediwith 171011 at all tlmeS- T0 a o plish this urth j i t t i l b i A th way pose I have selected various materials w ich being to furnish premoulded or preformed enter in the composition of the joint, the maconcrete sections poured against op osite t i s f j i t t i l ith th same i f terial being used selectively or collectively stallhd between the concrete sections. Usuf r ce -am pe lfi r as ns, an prepared in ally the strip is supported on edge and the a partlcular manner as Wlll hereinafter folsides of the same, so that it practically orms The Object f 1 expansion joint is to com an inseparable part of the sections, i. e. to P n for the P D nd contraction of Say a provision i d t insure th b 'd b the concrete sections.v At warm temperatures tween the sides of the joint and the concrete h confll'ete pan s, whleh' means'that this sections. 1 pgpanslon must be compensated for bythe Owing to the service that thei joint, in- 101D In other WOIdS, the jOlIlt Will be subtended 'to' perform and the difficulties to be le t0 PY e pressure from the sides, and expected in the performance of; the joint ununlessthe 1 n 1S p operly prepared, the tendusual 'care and scientific preparation of the 9 937- for the m terlal to ooze out of the joint i f th t t i t Si oint and spread itself on the surface of the a practically all concrete constructions are Where it Will e Pi ked up by passing effect of what is known as a test for brittleother object of m 'ness. In this test a piece'of joint about 6- overcome this de ectiveelongating of the built according to specifications, which also tmfllo {111d SPff r h I According embrace the joint material, it is'necessary to to mymv 'l Cell pr e thlS zing Of construct the joint to meet these 'specificathe j nd One of the objects of the same,

tions, otherwise the material is not acceptai t a c mplish this end. ble. As an example, most joint material is provided in the; form of strips, the dimencontract the tendency 18, Of C0l1'IS6,'t0 188N6- sions of which range from inch .to2 inches larger space n e joint. Consequently, in thickness and usually in lengths of 5 to 15 unless he joint material has the inherent feet, the width of the strip being the depth of quality of expanding from within ,it will not the wall surface or slabs between Which the- 11 up thisenlarged space in the joint. An-

strips are placed. These same dimensionsapother object of myinvention is-to provide a l f th t. t to poured j i t as ll joint material which will expand from-withas to moulded joints, in other words, in the ln soas to keep the space in the joint filled at case of a poured joint a space is left so that all tlmes. l

= In cold weather when the concrete sections I the joint when poured will boot a dimension The matter of elongation of the joint strip 1 required under the specifications. is also taken into account. When the con- Before the joint is installed in the, concrete crete sections expand and the pressure is imit must pass certain severe tests. As an exparted to the sides of the joint, the'joint has ample, the requirements for one of these tests a tendency, as above stated, to ooze, and it also calls for a material which will withstand the has a tendency to bechme elongated; s an invention I propose to inches square must not shatter or crack at joint, due to pressure on'the sides. 40 F., so that in cold weather the joint will Still another object of my invention is to not become brittle or fail'to function propprovide a joint which in the case of a pro I will first describe the materials entering into the manufacture of the joint and the function of the same when used selectively or collectively.

Owing to its inherent compressibility, resiliency and ductile qualities I prefer to use bituminous matter as a base for the composition of which the joint is produced, and more particularl I would prefer to use blown asphalt, as bituminous matter in this form serves the purpose to best advantage, primarily owing to the fact that it retains its resiliency, compressibility and ductile qualities after it has cooled off and has been moulded into a strip.

While, as stated bituminous matter in the form of blown asphalt is preferred, I do not wish to be limited to the use of this particular material as it is possible some other waterproofing material having the same characteristics may prove just as acceptable. In

any event, considering the base of the composition as comprising a waterproofing material having inherent compressibility and resiliency, and using blown asphalt as an example,I will proceed in producing material as follows:

By simply using a strip of bituminous matter even blown asphalt, certain difiiculties will arise which prohibit the joint being made with this material alone. In the first place, if it were made hard enough to handle properly it would be too brittle to compensate for expansion, and could not be properly handled in cold weather, as it would easily crack and even break. If it were made soft enough so as to compensate for expansion of the concrete, it would not only 000% outof the joint but in warm weather it would turn into practically a semi-fluid, in fact it would be out of the question to use this material without the aid of other materials to overcome these defects.

To overcome these conditions I propose to use certain materials in combination with a hinder or base, as I have referred to it, so as to make it practically what in effect is a composition of matter comprisin a binder and a frame structure within the binder, with this frame structure reinforced or strengthened,

and in addition a filler. This composition can be likened in many respects to the same theory as that concerned with the reinforcement of concrete. In other words, I incor- Eorate a binder with the material which will uild up a frame structure, with the frame structure reinforced by a different class of material and the whole increased in bulk by still another class of material. These three different groups of materials may be used with the binder selectively or collectively, in order to produce a joint material that will meet certain requirements.

As a morespecific embodiment of the composition I will classify the materials in groups, for instance, group A is a binder, such as blown asphalt or any other suitable waterproofed material. This binder will form the bulk or base of the joint material and serve to bind the other materials so that the composition may be, formed into strips, or in some instances poured into a mould. The purpose of the binder being to hold together the other materials used, to thoroughy waterproof the other materials, and to form itself under the motion of the concrete sections, and to adjust itself under pressure of traffic so that itwill work back into the joint and not permit itself to .be carried away by trafiic.

Group B, which is a frame building structure, preferably com rises such fibrous matter as bulk-vegetabe binder, fiat grasses, blades, fronds, roofing tabs, cypress bark, eucalyptus bark, hast, also similar binding strips, such as, flat strips of paper, flat excelsior, cloth and other flat materials having length. In other words, any material of the class described which will build up a framework structure in the binder. The purpose of this framework is to enable the strip to be handled without bending, wilting or slumping, and to prevent the binder from oozing in warm weather and becoming too brittle and shattering or cracking in cold weather.

Group C, which is a reinforcing structure, acts somewhat the same as the framework structure, except that the materials used in this group go further, due to their inherent strengthening qualities which reinforce the composition. For this group I prefer to select such fibres as cocoanut, sisal, hemp, mosses, jute or any other similar long fibre of strong qualit which rovides a relatively long, strong an tou h h rous material, having a surface slight y roughened or otherwise formed so as to allow the binder to again a thorough hold upon the fibre. As an example, while the material classified in group B, in some respects will enable the inding material to form a bond therewith, it ma not have enough strength or lon enougi surface area to form the right kin of a bond under certain conditions. At temperatures around E, if the binder does not have a thorough hold upon the fibre the tendency is for the fibres to slip, so to speak, in the binder. By usin such fibres as classified in group C I am ena led to overcome this possibility.

Asa second group coming under the head- Ill ing of reinforcing or-strengthening mediums, which may be used selectively or collectively with group C, I suggest group D, which consists of such fibrous matter as hog hair, cattle hair, horse hair, and other like strong fibre having a glossy and smooth surface,

which will resist pull increasingly at reduced temperature. Hair at warmer temperatures will slip through the binder,- but when the binder contracts and becomes set it grips the hair and the hair does not slip thru the binder. This isa particularly favorable material for use at temperatures ranging from 32 to 60 F. It also imparts resiliency and takes up shockin the material.

- was to be subjected to lower temperatures I would suggest the use of the material re ferred to in group D. As stated, the ma terials ingroups O and D may be used selectively or collectively.

As a filler to add bulk to the mass and reduce the weight of the binder I will classify the following materials as group E, the same consisting of such materials as cotton waste,

shoddy, roofing scrap and other finely divided ultimate fibres, such as, .wood pulp,

these materials to be utilized for the purpose of making up bulk. These materials will provide a fibrous filler of very short lengths distributed throughout the binding material, which will make the binder more sluggish and resist its tendency to flow under pressure. As a matter of fact the materials classified in group E are in one sense a flow controlling substance, and they would hard ly ever be used singly, that is to say, with simply-a binder Without the materials classified in groups C and D. They may be used in combination with either of the materials used in group C or D, or with botli groups of materials.

As a further group of materials to be used, viz, group F, I would classify; limestone dust, talc, mica, asbestos fibre or-clay, mostly all in the form of dust, which are placed upon the surface 0 the material to prevent adhesion or to fuuc ion in various Ways as a coating for the out ide of the material. 7

As an alternative coating medium in the composition I will refer to group G, containing a latexwash, gelatine, glycerine wash, polymerized oil, coating, gluten-glycerine, a rubber, solution, etc. The purpose of these materials being to take up surface shocks.

To make up the composition I will ordinarily proceed as follows: The binding material, such for instance, as asphalt, would be melted down to a. roper consistency so that it could bewor ed in a mechanical mixer. The materials classified in group E would then be incorporated, then the mate rials classified in roups C and D". As a matter of fact it oes not make much "difference in which order the materials are incorporated. TAfter the mixing thoroughly and without undue loss'of time, I, .would reduce the mass to sheets by subjecting the same to the'action of sheet forming rolls,

and thereafter cutting the sheets into strips.

the material into strips by a suitable extruding machine. j

The proportions of the material used are more or less important, for instance, the spec- As an alternative methodIgcould extrude ifications for expansion 'oint material call for Y a preponderance of bin ing material, such as asphalt. To meet these re quirements a suitable formula forthis composition would be seventy-five (7 5 per cent binding material, fifteen (15) per cent of a material classified in group B, three (3) per cent of a material per cent of a classified in groupC, two (22;r

p and five (5) material classifie" in grou The material classified in, group F may be used as a coating, and is simply dusted on the sides of the joint. In using any of the ma.- terials classifiedin grdu G asla coating the sameare applied as a lm or layer, asdesired. J a

Asa specific example ofa given mixture I refer to 50 to 60 lbs. of flat excelsior, 20 to 10 lbs. hemp or equivalent, 50 to 40 lbs. roofing scrap, 300 to 280 lbs. bituminous material. These proportions are simply illustrative of the possibilities. I have, of course, simply given the same as examples, and I do not care to be. limited to the proportions named. In any event, however, I would always use a larger percentage of binding material than any of the filling materials.

The two groups of reinforcing material may be more specifically referred to, for in stance, group C as a high temperature resistmg material and group D as a low temperaper cent, and flat linear elements composed" of fibers and relatively long, tenuous, vegetable fibres incorporated therein, the former providing a rigid. structural frame and .per cent of a materialclassified in group E.

building structure and relatively long animal ling bituminous material in excess hair, the animal hair providin an effective binding medium when the binder is at low temperature.

4. A preformed expansion joint mixed in the following proportions: 280 to 300 lbs. of bituminous material, 40 to 50 lbs. of roofing scrap, 10 to lbs. at long tenuous vegetable fibre, such as cocoanut fibre, 50 to 60 lbs. of flat excelsior.

5. A preformed expansion joint comprisof sixty per cent, flat linear material providing a rigid structural binder and two additional relnforcing means, each formed of relatively long, tenuous elements, one being particularly effective as a binding medium at high temperatures and the other being particularly effeetive as a binding medium at low temperatures.

6. A preformed expansion joint for concrete construction, eomprisinn a ductile, compressible binder in excess oi sixty per cent, relatively rigid, flat, reinforcing elements composed of fibers and long vegetable fibres and long animal hair.

Signed at Chicago, Illinois, this 1st day of May, 1926.

ALBERT C. FISCHER. 

